1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor sensor. For example, the sensor is used for detecting a physical amount such as an acceleration, a yaw rate or an oscillation.
2. Description of Related Art
A movable portion is disposed in a semiconductor sensor for detecting a physical (dynamic) amount, e.g., acceleration sensor or gyro sensor. However, durability performance of the movable portion is low due to its structure. Then, in order to reduce generation of defects, e.g., breakage, in a process for manufacturing the sensors, a cap is attached to a surface of a sensor chip including the movable portion.
For example, a cap is formed by layering a glass substrate or silicon on a sensor chip, according to US 2004/0025589 A1 (corresponding to JP-T2-2004-506203). The cap is formed over an entire wafer without being divided, on which plural sensors will be formed. However, an electrode pad has to be made in an exposed state in order to be connected to a sensor circuit. Therefore, a complicated treatment such as an etching or a grinding has to be performed. Further, a cost for manufacturing sensors may be increased, because the glass substrate or the silicon is used.
By contrast, in JP-A-2004-101528, a temporary cap made of resin is used in a variety of processes for manufacturing a sensor, and the temporary cap is removed after the processes are completed. However, the temporary cap cannot be used as a permanent cap, because durability performance of the temporary cap is low.